RUA

RUA is a build tool for ArchLinux, AUR. Its features:

• Allows local patch application
• Provides detailed information:
  • show upstream changes upon package upgrade
  • see code problems in PKGBUILD via shellcheck, taking care of special variables
  • warn if SUID files are present in an already built package, and show them
  • show file list, executable list and INSTALL script in already built archives
• Minimize user distractions:
  • verify all packages once, build without interruptions
  • group built dependencies for batch review
• Uses a security namespace jail:
  • supports --offline builds
  • builds in isolated filesystem, see safety section below
  • uses seccomp to limit available syscalls (e.g. the build cannot call ptrace)
  • the build cannot execute sudo (filesystem is mounted with nosuid)
• Written in Rust

Use

rua search wesnoth

rua info freecad

rua install xcalib # install or upgrade a package

rua upgrade # upgrade all AUR packages. You can selectively ignore packages by adding them to IgnorePkg in pacman.conf (same as with non-AUR packages and pacman). You can upgrade only specific packages with rua install A B C.

rua shellcheck path/to/my/PKGBUILD # run shellcheck on a PKGBUILD, discovering potential problems with the build instruction. Takes care of PKGBUILD-specific variables.

rua tarcheck xcalib.pkg.tar # if you already have a *.pkg.tar package built, run RUA checks on it (SUID, executable list, INSTALL script review etc).

rua builddir --offline /path/to/pkgbuild/directory # build a directory.

rua --help; rua subcommand --help # shows CLI help

Install dependencies

sh sudo pacman -S --needed git base-devel bubblewrap-suid lz shellcheck cargo

Install (the AUR way)

sh git clone https://aur.archlinux.org/rua.git cd rua makepkg -si In the web interface, package is rua.

Install (the Rust way)

sh RUSTUP_TOOLCHAIN=stable cargo install --force rua

This does not include bash/zsh/fish completions, but everything else should work. If you use development version pacman-git, use cargo install --features git rua instead.

How it works / directories

| directory | meaning | | ------------- | ------------- | | ~/.config/rua/pkg/ | Step 1, directory where AUR packages are cloned into. You review and make local modifications here | | ~/.cache/rua/build/ | Step 2, reviewed packages are copied here, and then built | | ~/.local/share/rua/checked_tars/ | Step 3, directory where built and tarcheck-ed packages are stored (*.pkg.tar.xz) | | ~/.config/rua/wrap_args.d/ | entrypoint for basic configuration of the security wrapper script | | ~/.config/rua/.system/ | internal files | | $GNUPGHOME/pubring.kbx
$GNUPGHOME/pubring.gpg | read-only access to these two files is granted when building, to allow signature verification |

All other files are not accessed by RUA and inaccessible by built packages (see Safety section below).

How it works / reviewing

Knowing the underlying machinery is not required to work with RUA, but if you're curious anyway, this section is for you.

All AUR packages are stored in designated git repositories, with upstream/master pointing to remote AUR head and local master meaning your reviewed and accepted state. Local branch does not track the remote one.

RUA works by fetching remote updates when needed, presenting remote changes to you and merging them if you accept them. Merging and basic diff view are built-in commands in RUA, and you can drop to shell and do more from git CLI if you want.

How it works / dependency grouping and installation

RUA will:

1. Fetch the AUR package and all recursive dependencies.
2. Prepare a summary of all pacman and AUR packages that will need installing. Show the summary to the user, confirm proceeding.
3. Iterate over all AUR dependencies and ask to review the repo-s. Once we know that user really accepts all recursive changes, proceed.
4. Propose installing all pacman dependencies.
5. Build all AUR packages of maximum dependency "depth".
6. Let the user review built artifacts (in batch).
7. Install them. If any more packages are left, go two steps up.

If you have a dependency structure like this: your_original_package ├── dependency_a │   ├── a1 │   └── a2 └── dependency_b ├── b1 └── b2 RUA will thus interrupt you 3 times, not 7 as if it would be plainly recursive. It also won't disrupt you if it knows recursion breaks down the line (with unsatisfiable dependencies).

Limitations

• This tool focuses on AUR packages only, you cannot -Suy your system with it. Use pacman for that.
• Optional dependencies (optdepends) are not installed. They are skipped. Check them out manually when you review PKGBUILD.
• The tool does not handle versions. It will always install the latest version possible, and it will always assume that latest version is enough.
• Development packages such as "-git" packages are only rebuilt when running rua upgrade --devel. No version checks are done to avoid unnecessary rebuilds. Merge requests welcomed.
• Unless you explicitly enable it, builds do not share user home (~). This may result in maven/npm/cargo/whatever dependencies re-downloading with each build. See safety section below on how to whitelist certain directories.
• Environment variables "PKGDEST" and "BUILDDIR" of makepkg.conf are not supported. Packages are built in isolation from each other, artifacts are stored in standard locations of this tool.
• Due of safety restrictions, X11 access might not work during build.
• Due to a bug in fakeroot, creation of root-owned packages inside PKGBUILD-s package() does not work. This happens when archives are extracted in package() function. Doing it in prepare() or giving a key like tar --no-same-owner is the work-around.

Safety

RUA only adds build-time safety and install-time control. Once/if packages pass your review, they are as run-time safe as they were in the first place. Do not install AUR packages you don't trust.

When building packages, RUA uses the following filesystem isolation by default:

• Build directory is mounted read-write.
• Files "$GNUPGHOME"/pubring.kbx and "$GNUPGHOME"/pubring.gpg are mounted read-only (if exists). This allows signature verification to work.
• The rest of ~ is not visible to the build process, mounted under tmpfs.
• /tmp and /dev and /proc are re-mounted with empty tmpfs, devtmpfs and procfs accordingly.
• The rest of / is mounted read-only.
• You can whitelist/add your mount points by configuring "wrapargs". See example in ~/.config/rua/.system/wrapargs.sh.example.

Additionally, all builds are run in a namespace jail, with seccomp enabled and user, ipc, pid, uts, cgroup being unshared by default. If asked from CLI, builds can be run in offline mode.

Other

The RUA name can be read as "RUst Aur jail", also an inversion of "AUR".

This work was made possible by the excellent libraries of libalpm, raur, srcinfo and many others.

IRC: #rua @freenode.net

Project is shared under GPLv3+. For authors, see Cargo.toml and git history.